My first tech job out of college, I worked with a lovely group of Chinese ladies. They gave me a Chinese nick-name meaning: dog nose.
Im working under the assumption that this wasnt an Anti-Semitic thing (lol!), but a comment on my really sensitive sense of smell. I would walk into the lab, smell gas, and be like “OMFG DID SOMEONE LEAVE THE GAS ON??” and they were like “Um, we had it on like 30 minutes ago…”
I hate cologne and perfumes. They literally make me ill (either sick to my stomach, if I can run away, or a migraine if I cant escape).
But I love, love, love the smell of a sweaty guy. Not like, sweaty guy socks, but a nice, fresh guy whose been outdoors and smells like sun + sweat… awesome *dreamy look*.
This probably has something to do with my particular genotype of OR7D4.
Absence of Evidence for MHC-Dependent Mate Selection within HapMap Populations—
There is evidence in numerous species that genes involved in immunity influence mate choice. Factors like body odor may subconsciously favor partners with different immunity alleles, to avoid inbreeding and/or endow offspring with broad resistance to pathogens. A previous study, based on HapMap genotypes, reported that European-American mates were extremely dissimilar from each other in immunity alleles compared to non-mates. Upon re-examining the results and methods, and visually comparing mates and non-mates, we found that this effect was weak, strongly dependent on extreme pairs and on arbitrary choices in methodology, and not significant after correcting for the multiple hypotheses tested. More importantly, examination of new couples from the same population did not support this hypothesis. Rare instances of very high MHC similarity among non-mates suggest that mates may avoid extreme similarity, rather than favoring dissimilarity. However, too few samples are readily available to test this prospect rigorously. We conclude that HapMap samples do not conclusively support the hypothesis that MHC genotypes exert an influence on mate choice. The same previous study reported that Yorubans appear to prefer mates who are more genetically similar to themselves overall. Our analyses suggest that the effect is driven by a subset of the sample.
Quick recap– Some people think that people are more attracted to people with different MHC alleles than they have. Mixing up these alleles is better for the future offspring. Mice have ways of ‘smelling’ this similarity/difference of other mice, and choose opposites. Humans dont have the organ we would need to ‘smell’ differences anymore. People keep publishing this stuff anyway.
So these folks looked at the data from other people who had published on this topic, saying that humans DO select for opposites (even though we have no VNO and there is no alternative biochemical pathway suggested). They looked at data from Mom-Dad-Baby trios to see who females and males actually picked as their mates, and the resulting MHC-type of their offspring.
Basically, a few outliers were skewing the data, and there is not much of an impact of MHC-type and humans hooking up:
We found that the previously reported MHC dissimilarity among Hap2 European-American mate pairs is apparent but not robustly supported by the underlying genotypic evidence. In addition, the effect essentially disappears in Hap3 for a similar number of independent couples from the same population, and is weak and insignificant for the combined Hap3 cohort.
So unless there is some big revolution in MHC-mates (figure out a plausible biochemical pathway, nice robust data), Im going to be leaving this field of research in the ‘woo’ file.
Hat tip to sweaty Scibling Blake 😉